硬质合金混合料制备新工艺特征分析

Characteristic analysis on new preparation technique of cemented carbide slurry

针对超细硬质合金混合料制备过程中出现的研磨与分散问题, 开发了一种混合料制备新工艺。采用扫描电镜、X射线能谱仪以及金相显微镜对分别采用传统工艺与新工艺制备的WC 8%Co硬质合金脱蜡压坯断面WC与Co的分布、合金烧结体表面粘结相与WC硬质相的分布以及合金的组织结构进行了对比研究, 揭示了硬质合金混合料制备新工艺具有较高的研磨与分散效率的特点。新工艺的研磨与分散机理是: 通过混合湿磨介质的表面活性剂效应, 促进湿磨介质在粉末颗粒缺陷处的渗透, 从而促进粉末颗粒的破碎与团聚体的分散; 通过表面活性剂稳定与高分子稳定的作用, 阻止湿磨过程中粉末的团聚。

Focused on the grinding and dispersion issues in the preparation of ultrafine-cemented carbide slurry, a new technique for the preparation of cemented carbide slurry was developed. The distribution of WC and cobalt / binder on the cross section of the de-waxed green compacts and the sinter skins, and the microstructures of WC-8%Co cemented carbide prepared by conventional and new techniques, respectively, were studied by SEM, EDXS and optical microscope to identify the character of the new technique. It is shown that the new technique can be characterized by high efficiency of grinding and dispersion, which is due to the surfactant effect of the multicomponent ball-milling medium and the particle-stabilization effects of the surfactant and macromolecule. The former facilitates the penetration of the milling medium through the defects of particles and thus facilitates the fragmentation of particles and aggregations; the latter can prevent the agglomeration of the cracked particles.